A Study of Electromagnetic Induction in HVDC Lines From Parallel AC Lines Under Short Circuit Conditions

High Voltage Direct Current (HVDC) lines running parallel to AC transmission lines will encounter electromagnetic induction which will rise to substantial levels during a short circuit. The actual magnitude of induced current depends on several factors like distance between the lines, soil resistivity etc. The unenergised DC line will also have a voltage due to induction and the associated discharging equipment will have to carry the induced current. This paper attempts to study the levels of induction encountered by the HVDC line and associated equipment during a short circuit in the AC line. It was observed that magnitude of induced current during steady state and three phase fault did not exceed 5 A while the magnitude of induced current during single phase to ground fault exceeded 15 A