Capacitor bank provided with a protective device

Abstract

A capacitor bank comprising a plurality of capacitor units coupled in parallel, and an energy absorbing resistor Rj is inserted in series with each one Cj of the capacitor units. Thus, when a capacitor unit Cj suffers an insulation failure, the energy flowing into the failing capacitor unit Cj from the other capacitor units is absorbed substantially by the resistor Rj. The capacitor bank may comprise several serially connected rows of parallel connected capacitor units, an energy absorbing capacitor Rij being inserted in series with each one Cij of the capacitor units. Further, each capacitor unit Cj may be provided with a protective short-circuiting device Sj, which short circuits the two terminals of the capacitor unit Cj via a bypass line 9 upon an occurance of failure of the capacitor unit Cj. An oscillation preventing resistor Ry is connected in series with each capacitor unit Cj in addition to an energy absorbing resistor Rx.