Abstract: A magnetic structure (60) comprises input and output stages (61, 62) comprising a yoke (61c, 62c) and at least two cores (61a, 62a), and at least one intermediate stage (63) with cores (63a) magnetically coupled to the input and output stages. By providing gaps (64) with magnetic permeability and high electrical voltage withstand capability providing magnetic coupling between the stages, poles (61d, 62d, 63d), which expand the cross-area of the cores, wherein the poles from adjacent stages are provided on opposing sides of the gaps (64), thereby providing magnetic coupling across the gaps (64), and windings (61b, 62b, 63b) provided on the cores, a transformer with extremely high is provided.

Abstract: An arrangement for interrupting current comprising a first and a second terminal adapted to electrically connect two sections of a power system is provided. A voltage control means is controllable in use to inject energy into said loop to force a rapid increase of an alternating current flowing through said main branch while being controlled to open to interrupt a main current, and whereby zero cross-over of the current through the mechanical main circuit breaker is realized as the amplitude of the alternating current exceeds the amplitude of the main current. An energy absorbing device is adapted to limit the voltage across said capacitor and said mechanical breaker when the mechanical breaker is open, and across an inductive element if the voltage across the mechanical breaker breaks down, at or immediately after an opening process, thereby limiting the rate-of-rise and the peak of the current through said loop.

Abstract: An arrangement for interrupting current comprising a first and a second terminal adapted to electrically connect two sections of a power system is provided. A voltage control means is controllable in use to inject energy into said loop to force a rapid increase of an alternating current flowing through said main branch while being controlled to open to interrupt a main current, and whereby zero cross-over of the current through the mechanical main circuit breaker is realized as the amplitude of the alternating current exceeds the amplitude of the main current. An energy absorbing device is adapted to limit the voltage across said capacitor and said mechanical breaker when the mechanical breaker is open, and across an inductive element if the voltage across the mechanical breaker breaks down, at or immediately after an opening process, thereby limiting the rate-of-rise and the peak of the current through said loop.