National grid turns a new page

What do you say about the North-South 500 kV transmission line after two decades of operation?

As of March 2014, the Vietnam Electricity Group National Power Transmission Corporation (EVNNPTC) had securely transmitted nearly 560 billion kWh, with an annual average growth rate of about 10 percent. The incident rates for the lines and transformer stations were lower than catered for.

 Maintenance of the North South 500kV transmission lines

Over the past six years, EVNNPTC has invested more than VND61 trillion in 244 500kV works including 220 kV transformer stations. Particularly in 2013 and the first four months of 2014, EVNNPTC already put into operation many important 500kV lines linking Phu My-Song May, Song May-Tan Dinh, Vinh Tan-Song May, Quang Ninh-Mong Duong, and Pleiku-My Phuoc-Cau Bong; Song May Transformer Station, and Cau Bong Transformer Station. To date, the 500kV grid system has ensured power supply to major cities and key economic hubs such as Phu My, Song May, Tan Dinh, Phu Lam, Nha Be, Son La, Hiep Hoa, Quang Ninh, Thuong Tin, Nho Quan, and Hoa Binh.

In particular, EVNNPTC decided to use static VAR compensators for the North-South 500kV transmission lines to enhance line secondary capacity and therefore, the transmission capacity on the two circuits of the 500kV North-South power transmission lines has been increased up to 1600-1800MW, reaching an annual transmission output of more than 12 billion kWh, a six-fold increase compared to the designed capacity. The national grid has reached 60 of 63 provinces and cities across the country and gradually connected to the regional transmission grids.

Many technological applications have been applied to the national transmission grid such as multi-circuit and multi-voltage levels, 220kV GIS stations, computerized control systems, incident positioners, online oil monitors, and SCADA systems.

Investment has failed to keep up with the pace of the grid’s development. So, what will EVNNPTC do to remedy this situation?

EVNNPTC has focused all efforts on ensuring power transmission security and stability. It will strive until 2020 to have a smart transmission grid meeting N-1 and N-2 reliability standards and annually transmitted power outputs from 265-275 billion kWh; We intend to see 100 percent of transformer stations meeting ISO 14001 environmental standards./.                                      

Source: VEN