The nominal capacity of each substation will be 3,000 MW and they will be located near the existing Kimal substations, in the Antofagasta Region, and Lo Aguirre, in the Metropolitan Region.

Tuesday, September 17, 2024.-
The Kimal-Lo Aguirre transmission project will bring several innovations to the National Electric System (SEN) by becoming the first to use direct current, the most widely used technology in the world to safely and efficiently transport energy over long distances.
One of the main components of the direct current link are the HVDC or direct current substations, which convert energy from alternating current to direct current and vice versa, which will be located at both ends of the line, so that they can receive the renewable energy produced in the north of the country and supply it in the central area of ​​the country with minimal losses.
“A substation is an infrastructure created to receive the energy generated by power generation plants and ensure the proper conditions for the energy to be transported,” says Mauricio Restrepo, Manager of Engineering and Construction of Converter Substations.
The executive adds that “in the case of Kimal-Lo Aguirre, the converter substations will receive the energy in alternating current and transform it into direct current, which will then be transported along a 1,342 km long line, to the center of the country, to convert it back into alternating current and inject it into the National Electric System, contributing to the decarbonization of the country.”
One substation will be located near the existing Kimal substations, in the commune of María Elena, Antofagasta Region, and the other, in the current one near the Lo Aguirre substation, in the commune of Pudahuel, Metropolitan Region.
Substations inside
To give an idea of ​​the facilities, the converter substations will have an area of ​​15 to 16 hectares each, which will be equivalent to 20 soccer fields. At one end is the alternating current yard, which allows the connection of the alternating current lines with the substation, with a special design to reinforce the reliability of the arrival of the alternating current lines, and with special filters that guarantee the quality of the energy conversion.
Then there are the transformer yards where the alternating current voltage is brought to a level suitable for its conversion to direct current.
This finally occurs in a place called the valve room, which is finally connected to the direct current yard, where the equipment that links the station with the direct current transmission line is located.
Throughout the process, safety is a key element. An example of this is the double protection system so that there is a backup in case of failures. There will be redundant cooling for the valves and for the statcom system, which will have two water pumps in parallel, which will operate alternately, and in case one of the pumps fails, the other can supply the cooling requirements of the entire system.
In addition, all the equipment in the converter substation will have seismic validations, which guarantees compliance with national regulations and allows for a safe project to advance in the energy transition.
It should be noted that the converter transformers that will be part of the HVDC substations will be the largest transformers installed in the SEN. Each substation will have two banks of 1,770 MVA transformers each. In the case of Kimal, they will weigh around 600 tons and will be 12 meters long, 4 meters wide and close to 14 meters high. As for Lo Aguirre, the transformers will weigh around 500 tons and will be 13 meters long, 4 meters wide and approximately 10 meters high.
Advantages of the project
– The entire control and protection system will be digital, using fiber optics to replace traditional copper cables.
– Fewer cables are used than those required in an alternating current substation.
– Reduction in installation and testing times during the construction phase.
– Greater safety in maintenance tasks and protection for workers.
– Solutions in alternating current yards with a switch and a half, which provides greater reliability in the connection of alternating current lines in the substations and connection to the transformers.
Description of the Kimal-Lo Aguirre project.

The project will be the first in direct current to be built in Chile, although it is a technology that has been used for years to transport renewable energy to consumption centers.
It is a key piece in decarbonization, as it will help reduce the discharge of energy that cannot be transported due to the lack of new power transmission lines, and which in the first half of the year registered an increase of 164% compared to 2023.
Along 1,342 kilometers, the project will be able to transmit a power of 3,000 MW, equivalent to a quarter of the maximum daily demand registered in the SEN during 2023. It was tendered by the State through the National Electric Coordinator and awarded to the company Conexión Kimal-Lo Aguirre in 2021.