Some aspects of steady state simulations of AC/DC hybrid transmission lines

The use of hybrid AC/DC overhead transmission lines is an option to increase the power line transport capacities and to reduce the width of the right-of-ways. On the other side the proximity of power circuits of different rated voltages and frequencies on the same tower intensifies interferences between power circuits. One of undesirable effects of the proximity of AC and DC power circuits is possible penetration of DC components into AC power circuits. DC components can saturate the magnet systems of transformers and disturb the network operation. In the paper is shown that the neglection of some aspects of the transmission line steady state modeling can cause erroneous estimation of the DC components in the simulated AC power circuits of AC/DC hybrid transmission lines.