Research on corona discharge suppression of high-voltage direct-current transmission lines based on dielectric-film-covered conductor

Abstract

Corona discharge suppression for high-voltage direct-current (HVDC) transmission lines at line terminals such as converter stations is a subject that requires attention. In this paper, a method based on a conductor covered with dielectric film is proposed and implemented through a bench-scale setup. Compared with the bare conductor, the corona discharge suppression effect of the dielectric-film-covered conductor under positive polarity is studied from the composite field strength and ion current density using a line-plate experimental device. The influences of film thickness and film material on the corona discharge suppression effect are investigated. The charge accumulation and dissipation characteristics of different film materials are also studied. The results show that the conductor covered with dielectric film has excellent ability to inhibit corona discharge. The ground-level composite field strength of the conductor covered with dielectric film is lower than its nominal field strength, and its ion current density is at the nA m−2 level. The corona threshold voltage can be promoted by increasing the film thickness, but the ability to inhibit corona discharge becomes weak. The larger the surface electric field strength, the more charge accumulated, but the faster the charge dissipation rate. Compared with polyvinyl chloride film, cross-linked polyethylene film has stronger charge accumulation ability and slower charge dissipation rate, which can better restrain the corona discharge of HVDC transmission lines.

Research on automatic maintenance method of flexible maintenance robot for heating defects of high voltage transmission lines

“…In formula (6), d represents the grid of maintenance nodes, x represents the horizontal maintenance node, s represents the length of maintenance planning path, y represents the longitudinal maintenance node. Combined with the above formula, it can effectively compensate the automatic maintenance positioning error of the flexible maintenance robot for thermal defects, and improve the accuracy of automatic maintenance.…”

“…Under the influence of transmission load, voltage, etc. [4][5][6], high-voltage transmission lines are prone to overload problems, resulting in heating defects, which will not only cause abnormal operation of transmission lines, but also may cause large-scale safety accidents. If the intelligent device can effectively identify and repair the heating defects of high-voltage transmission lines, it will greatly reduce the risk of overheating accidents [7][8][9][10] and the maintenance cost of high-voltage transmission lines.…”

Anti-collision alarm system of crane against high-voltage lines based on multimodal information

“…The third generation of crane anti-collision system, which is designed and manufactured by SMIE company in France, is the most representative. The principle of the system is to restore the crane construction site represented by graphics through computer simulation, so that the crane operator can observe the dynamic of the crane in real time to avoid the accident [6] . However, the system has high integration, poor compatibility, high price, and is not easy to install, so the system is not fully applicable to most cranes.…”

“…The Crane Ranger system, which has been investigated by the Siemens, is also to avoid collision. The aim of Crane Ranger system is to measure the distance between the crane and obstacles with ultrasonic technology, and then the crane anti-collision algorithm is adopted to prevent the collision between the crane and the high-voltage line [7] . Besides, CRANE is mainly engaged in crane lineless monitoring system [8] .…”

A novel fault current limiter topology design based on liquid metal current limiter

“…When the short-circuit current approaches or exceeds the existing breaker capacity, the current seriously endangers the safety of the power grid, which thus limits the further development of power grids. Limiting short-circuit currents has become a key challenge [1][2][3][4].…”