Surge arresters for lines
The installation of lightning arresters (LA) for substations in Vietnam has been used since the 35kV power grid was established, but the transmission lines were just from 2012-2013.
To reduce incidents caused by lightning, units under EVNNPT have implemented many solutions, including the solution of equipping LA at column locations in areas with high thunderstorm density and high soil resistivity, on rocky terrain, at positions of power columns with high height, at locations with high elevation above the water surface, large power column spans often occur many incidents due to lightning; lines are located in areas with high lightning density and go on high hills, poles with soil resistivity of 3000ᾭm or more and poles are frequently struck by lightning, etc.
The installation of LA is a solution that contributes to reducing the lightning incidents for the line.
Thanks to the positioning devices, early and fast detection of violation risks of the grid safety corridor made
Installing a camera for the line
Up to now, units under EVNNPT have equipped hundreds of cameras for monitoring lines at column locations where construction works are under construction; crossing roads and waterways – places with a lot of traffic; easy collapse of column foundation; column area with a high risk of forest fire; transmission line area where people often fly kites; crossing internal roads of industrial parks where trucks often pass by. The camera signal is sent to the line team to monitor the line status and detect corridor violations.
During the rainy and stormy season, through images transmitted from cameras, the management unit can view the current status without approaching the site, thereby confirming the operation status of the grid quickly. The camera is also capable of storing images, so it can retrieve traces to serve the investigation and analysis of the right causes when there are abnormalities, violations of the corridor.
Positioning the line incident location distance
Up to now, units in EVNNPT have equipped dozens of incident point distance locators for most of the important and long 500 and 220kV transmission lines. The installation of these devices has brought many efficiencies to operation management such as reduction. Currently, EVNNPT is still directing the units to continue to propose equipping adequate locators in the near future.
Lightning information collection, monitoring and warning system
To gain complete information about lightning for the design, operation, repair and reduction of incidents caused by lightning, EVNNPT has invested in equipping a lightning warning collection system, helping to promptly identify the location of a lightning fault and analyze its cause.
Currently, EVNNPT has completed the investment and equipping for the North and North Central regions and is deploying it for the South Central and Southern regions.
Unmanned aerial vehicle - UAV
Since 2018, EVNNPT has piloted the application of UAV. Units have also built and improved UAVs for the purpose of burning kites entangled on conductors and lightning wires, and so on.
The equipping of UAVs has brought many benefits to the inspection, management and operation of live lines, reducing inspection time, reducing labor, and improving labor productivity; limit the danger to workers and ensure the safety of people and lines when inspecting live overhead items.
Up to now, the units under EVNNPT have equipped dozens of UAV sets to serve the management and operation of the line and they are continuing to retrofit to ensure that they can meet the requirements for production. In addition, units that have used UAVs have conducted a periodic inspection of lines, inspection after incidents, inspection of corridors, the status of column foundation landslides, and so on.
In addition, units in EVNNPT are also researching and deploying AI applications to analyze images from photographic equipment, cameras and UAVs using AI to identify/classify abnormal/normal failures inline testing.
To further ensure the safe, reliable and stable operation of the transmission network and improve labor productivity, EVNNPT is actively researching and deploying more modern and automatic technologies to bring efficiency for the management and operation of the transmission grid such as deploying digitization of line equipment information on PMIS technical management software, standardizing data according to CIM model, building Dashboards, deploying tools of intelligent analysis, with a customized interface, so that objects in the engineering block can exploit information from the PMIS system.
The application of line dynamic rating (DLR) technology is also being deployed to improve the optimal capacity inline operation management with real parameter monitoring, operation with optimal line capacity according to environmental conditions, monitoring capacity, deflection, line temperature by using data on weather conditions in the area such as speed, wind direction, ambient temperature, solar radiation to calculate the transmission capacity of the line in real-time in the most economical and efficient way.