Total eddy currents induced in screens of a symmetrical three-phase single-pole gasinsulated transmission line (GIL)

Abstract

In the paper we discuss the question of eddy currents induced in screens of a symmetrical three-phase singlepole gas-insulated transmission line (GIL). First, we determine the eddy currents induced in the tubular screen by the magnetic field of self-current of the phase conductor. Then the magnetic field in the external parallel phase conductor is presented by means of a vector magnetic potential as Fourrier series. In the non-conducting external and internal area of the screen we use Laplace equation for the magnetic field strength taking into account the reverse reaction of eddy currents induced in the screen. In the conducting screen we apply Helmholtz equation for eddy currents density. Using classical boundary conditions we determine the density of the currents. The solutions obtained are used to determine the total eddy currents induced in all the screens of the GIL under consideration.