Experimental study on the influence of climatic conditions on the formation of ion currents at transmission line conductors under DC stress

Due to the arising demand for an increased transmission capacity and flexibility of the German transmission grid, the system operators have agreed on the integration of high voltage DC transmission (HVDC) into the existing German transmission system. Considering this development of the transmission grids, additional knowledge with regard to physical phenomena, e.g. corona discharges occurring at the surface of the conductors, becomes more and more important. For this purpose, an experimental setup based on a cylindrical corona cage, is developed in this research work for investigating the dependencies of ion currents in DC electric fields on climatic conditions implying temperature values in the range of ? = -15…40 °C and relative humidity values of ? = 20…90%. First experimental results…