Earlier, on July 26, EVNNPT deputy general director Nguyen Ngoc Tan, who also chairs the investor-level acceptance council, had presided over a meeting to approve key phases of the project.

Although construction wrapped up in July, the project’s phase 1 energization was delayed until Monday (August 4) due to scheduling requirements for a suitable power outage to connect live and non-live components.

The upgrade is a special-grade energy project classified as Group B, with EVNNPT - a subsidiary of state-owned giant Vietnam Electricity (EVN) - as the investor; NPTPMB as project manager; and Power Transmission Company No.1 in charge of operations.

The project was carried out within the existing Viet Tri substation site in Phu Tho province.

The substation is currently operating with two 500kV-450MVA transformers. Under the upgrade project, its total capacity will be increased to 1,800MVA.

Specifically, during phase 1, a new 500kV-450MVA AT3 transformer was installed, raising the substation’s capacity to 1,350MVA. The 500kV busbar scheme was also upgraded from a closed-ring layout to a breaker-and-a-half configuration.

In phase 2, the existing 500kV-450MVA AT2 transformer will be upgraded to 500kV-900MVA, bringing the substation’s total capacity to 1,800MVA.

A representative of the NPTPMB said the project faced numerous challenges, including a tight execution timeline mandated by EVN, while still having to comply with all regulatory procedures. In addition, construction took place under live and heavily loaded conditions at the substation, making it difficult to schedule power outages.

However, under the close and continuous oversight of EVNNPT leadership, the project stayed on track, supported by detailed daily and weekly plans developed by EVNNPT and NPTPMB to guide execution.

Thanks to close coordination with system operators and strong support from Power Transmission Company No.1, the project was completed on schedule in line with EVN’s directive.

The project helps strengthen power supply amid peak summer demand in northern Vietnam. It ensures long-term, reliable electricity for regional socio-economic development, enhances grid stability and transmission capacity, reduces power losses, and improves EVN’s operational efficiency.

The energization marks a meaningful contribution by EVNNPT and NPTPMB in celebration of EVN’s 4th Party Congress for the 2025-2030 term, as well as the 80th anniversary of the August Revolution (August 19) and National Day (September 2).