Abstract: An arrangement for interrupting current comprises a first and a second terminal. First, second, and third parallel circuit branches are arranged between the terminals to electrically connect two power networks. The first parallel circuit branch comprises a mechanical main circuit breaker, the second parallel circuit branch comprises an energy absorbing device, and the third parallel circuit branch comprises a resonant circuit and a voltage control means arranged in series. The voltage control means is controllable to inject energy into the resonant circuit to force a rapid increase of alternating current, wherein the alternating current flows in a loop containing the first and the third parallel circuit branches as the mechanical main circuit breaker is controlled to open to interrupt main current. Zero cross-over of the current through the mechanical main circuit breaker is thereby realized as the alternating current amplitude exceeds the main current amplitude.

Abstract: A circuit breaker comprises a switch and an actuator comprising a displaceable shaft mechanically connected to a movable contact in the switch. A Thomson coil is adapted to displace the shaft in a first direction, and a disconnecting device is connected in series with the switch and that is adapted to open during an interval when current is extinguished. An energy storage is provided being a separate part from the shaft and being adapted to store energy when the shaft moves in the first direction and to release energy to displace the shaft in a second direction, comprising a mass-spring arrangement with a body, a first spring between the shaft and one end portion of the body at a side facing the shaft and a second spring at a first end portion connected to a side of the body facing from the shaft and at second end portion being fixed. The movement of the body continues undisturbed to achieve a time interval wherein a current is extinguished.

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: A circuit breaker comprises a switch and an actuator comprising a displaceable shaft mechanically connected to a movable contact in the switch. A Thomson coil is adapted to displace the shaft in a first direction, and a disconnecting device is connected in series with the switch and that is adapted to open during an interval when current is extinguished. An energy storage is provided being a separate part from the shaft and being adapted to store energy when the shaft moves in the first direction and to release energy to displace the shaft in a second direction, comprising a mass-spring arrangement with a body, a first spring between the shaft and one end portion of the body at a side facing the shaft and a second spring at a first end portion connected to a side of the body facing from the shaft and at second end portion being fixed. The movement of the body continues undisturbed to achieve a time interval wherein a current is extinguished.