Corona discharge characterization and electromagnetic effects of HVDC transmission lines
The concept of high voltage direct current (HVDC) power transmission was emerged in the mid-1920s as an alternative to conventional AV power transmission and the first commercial HVDC link was realized in 1954 with mercury arc rectifiers. Following the developments in semi-conductor thyristor technology, HVDC transmission projects have shown to offer significant electrical, economic, and environmental advantages when transporting power across long distances.
HVDC technology is suitable for certain applications due to some advantages over AC systems. However, environmental effects of HVDC transmission are still under consideration. The corona characteristics of DC transmission lines are different from those of AC lines mainly because of the different magnitudes of the space charges produced by ionization processes between the line conductors or between the conductors and the ground.
This project is therefore devoted to characterize the corona discharge and the electromagnetic effects of HVDC links. The project includes both the simulation and experimental studies for country specific cases for Turkey and Mexico as well as for several technical configurations including single and bundle conductors, unipolar and bipolar configuration and conductor spacing. Most of the studies so far have concentrated on the transmission line performance and almost nothing has been done for complete insulator strings. This study will fulfil this gap since the complete section of a transmission line will be considered in the simulations and the experiments. Moreover, insulator performance and contamination impacts on corona characteristics will also be addressed. Finally, several tests will be performed both at a sea level (Turkey) and at high altitudes (Mexico) to account the effects of the altitude.
Keywords: HVDC, Corona Characteristics, Corona Current, Audible Noise (AN), Radio Interference (RI), Finite Element Method.