SGBH completes Brazil's first hotline maintenance of ±800kV UHV transmission line
State Grid Brazil Holding (SGBH) successfully completed live-line working at a transmission tower of the Phase II (XRTE) Belo Monte ±800kV UHV DC line in Brazil. This marked the first hotline maintenance of a ±800kV UHV line in Brazil. Accomplishing this tough operation at a high voltage level was also the first of its kind in Brazil.
During the maintenance, the team lead gave instructions according to safety procedures. Two maintenance staff, properly dressed in shielding clothes, climbed to the cross arm of the tower. Assisted by five teammates, they each took the hanging basket and slowly approached the UHV line by the paying off pulley. With a conducting rod in contact with the wire, the maintenance staff entered the electric field and did the equipotential live-line working. The whole operation took two hours from preparation to completion. They safely remedied two defects by replacing the spacer and repairing the surface damage of the cable. The operation improved the operational stability of the transmission line and avoided a maintenance outage that would probably impact the annual permitted revenue (RAP).Since 2020, SGBH has been exploring how to do live-line working for the ±800kV UHV DC line. It participated in tests of shield clothing and contributed to test findings certified by the Brazilian Ministry of Labor in September 2022. Before the operation, the maintenance team had made full preparation, technically verified each step, inspected the tools, and formulated safety measures for insulator and spacer replacement of the ±800kV UHV DC line. The team visited the site for many times, carried out training and simulation under non-live conditions, and familiarized themselves with the setting and the maintenance process. Such preparation laid a solid foundation for the safe and smooth implementation of the hotline maintenance.
The operation marked SGBH’s successful translation of research findings to the practice of hotline maintenance for the ±800kV UHV DC line. It also demonstrated the company’s technical prowess at live-line working. Going forward, SGBH will sum up experience in the operation, improve safety measures and tool management as part of its efforts to advance the lean management of live-line working, to ensure safe and efficient hotline maintenance. Thus the company will be able to save time in repairing defects, and ensure the safe and stable operation of high-voltage transmission lines. SGBH will continue to contribute to the Belt and Road Initiative, to its parent company State Grid’s high-quality growth, and to the vision of building a world-leading energy internet enterprise with Chinese characteristics.
Source: State Grid International Development Co., Ltd. (SGID)
