Part 3: The national power grid runs smoothly from North to South via the 500kV ultra-high voltage line, circuit 1 (Period 1986-1994)

The national power system was formed based on connecting the power grids of the North - Central - South regions through the "backbone" axis of the 500kV power transmission line - an event marking the remarkable growth of the construction, transmission, operation, and dispatching team of the national power system.

Period 1986-1990

On February 16, 1987, the National Assembly Standing Committee issued a resolution to establish the Ministry of Energy based on unifying the Ministry of Electricity with the Ministry of Mines and Coal. Mr. Vu Ngoc Hai was appointed as Minister.

In the North, from 1985 to 1988, the power shortage was still serious. By the end of December 1988, Unit 1 of the Hoa Binh Hydropower Plant was put into operation, followed by 1 to 2 more units being put into operation every year, increasing electricity output by 20%, creating a qualitative change in the Northern power system. In addition, electricity brought to the Central region contributed to solving most of the power shortage in this region.

- From 1986-1990, implementing the policy of electricity serving the economic and cultural development of mountainous areas, the Power sector constructed and put into operation the Thai Nguyen-Cao Bang 110kV power line, the Tuyen Quang 110kV substation (in 1990), the Moc Chau-Mai Chau, Cam Pha-Tien Yen lines and the Tien Yen 110kV substation, etc., thanks to which the national grid (110kV) reached mountainous, remote, and isolated areas.

Tri An Hydropower Plant in early days of construction. Source: cosodulieu.evn.com.vn

In the Central region, by September 30, 1990, the North Central region has 446km of high-voltage lines, including 203km of 220kV lines, 172km of 110kV lines, 91km of newly built double-circuit lines, and 4 110kV substations with a total capacity of 73MVA safely put into operation.

After that, the Vinh-Da Nang power line was safely put into operation, increasing the Central region by 30 - 35MW. Since then, the Central region has had a daily electricity output of 600,000-700,000kWh, meeting 80% of the electricity demand of the 4 Central provinces.

In the South, by the end of 1990, the total electricity capacity of the whole region was 1,031.8MW (of which hydropower accounted for over 50%). Tri An Hydropower Plant (400MW) came into operation, other thermal and hydropower sources were consolidated.

High and medium-voltage grids were developed and expanded.

From 1986 to 1990, the Power sector constructed an additional 93km of 220kV lines, 850km of 110kV lines, 476km of 35kV lines, 2,042km of 15kV lines with 4 220kV substations (total capacity of 625MVA), 16 110kV substations (total capacity of 1,037MVA), dozens of other intermediate stations with a total capacity of 231.5MVA.

Period 1991-1994

In the North, 8 units of Hoa Binh Hydropower Plant were synchronized to the national power grid, officially completed after 15 years of construction (December 20, 1994).

With a length of nearly 1,500km from Hoa Binh to Phu Lam, the North-South 500kV ultra-high voltage transmission line, circuit 1, commenced on April 5, 1992, inaugurated and energized on May 27, 1994. This is the first ultra-high voltage power project, completely new in terms of technique and technology for the Vietnam power sector. The 2 years completion of the project is a miracle in terms of construction speed, demonstrating the determination, efforts, and intelligence of Vietnamese electricity workers, which is considered by the world as "amazing".

From this time, the national power system was formed based on connecting the power grids of the North - Central - South regions through the "backbone" axis of the 500kV transmission line - an event marking the remarkable growth of the construction, transmission, operation, and dispatching team of the national power system.

On April 11, 1994, the National Load Dispatch Center (A0) was established to operate the entire power system of the 3 regions. The first director of A0 was Mr. Tran Minh Kham.

Hoa Binh Hydropower Plant. Source: Huynh Van Truyen

In the Central region, the power sector has undergone strong changes, especially when Vinh Son Hydropower Plant (66MW) came into operation at the end of 1994. The power output by the end of 1994 reached 1.031 billion kWh, an increase of 11 times compared to that of 1976. Of which, electricity for industry increased by 14 times, agriculture increased by 17 times, and daily life increased by 7 times. Average power output per capita reached 115 kWh/year, an increase of more than 8 times compared to the liberation day.

In the South, in the early 90s of the 20th century, there was a severe electricity shortage. The power sector proposed to the Government to allow the import of 2 mixed gas turbines installed in Ba Ria, forming the Ba Ria (Vung Tau) 200MW Power Plant; After that, Thac Mo Hydropower Plant (150MW) and a cluster of gas turbines of Thu Duc Thermal Power Plant (100MW) generated electricity to the grid, along with the electricity received from the North via the 500kV transmission line, the power shortage in the South was reduced. From 1990-1994, electricity in production increased by an average of 12%/year.

We invite readers to continue following Part 4: Meeting sufficient electricity for the country's industrialization and modernization needs (Period 1995-2015)

Translator: Thu Hường