Abstract: A device for continuous or semi-continuous casting of metals, comprising a casting mold (1) which is open in both ends in the casting direction, means (2) for supplying melt to the mold (1), a first electromagnetic induction coil (4) energized by A.C. current and adapted to induce a stirring motion to the melt (7) in the mold (1), and a second electromagnetic induction coil (3) arranged upstream of the first induction coil (4) and adapted to control the stirring motion of the melt in the region adjacent to the upper free surface (5) of the melt. The second induction coil (3) is arranged to be interchangeably energized by either D.C. or A.C. current. The invention also relates to methods for control of stirring motion in a casting mold (1).

Abstract: An apparatus for controlling an electric switching device (1) for alternating current arranged in a current path for opening the switching device and for breaking the current in the current path after occurrence of a fault current comprises members (15) adapted to detect the current in the current path and a unit (20) adapted to control the electric switching device to break the current in the current path directly after a half wave of the alternating current having a peak value below a predetermined current limit value, so that the breaking is completed through a zero-crossing of the alternating current terminating a said half wave.

Abstract: An apparatus (14) for detecting a zero-crossing of an alternating current after occurrence of a fault in a current path (2) for determining a suitable time for opening an electric switching device (2) arranged in the current path for breaking the current in the current path comprises members (15) adapted to detect the current in the current path. An arrangement (19) is adapted to calculate the dc-level of the current and the decay of the dc-level with time on the basis of values of the alternating current detected and also predict the time for a future zero-crossing of the alternating current on the basis of at least current values obtained through said current detection, the dc-level calculated, the dc-decay calculated and information about the period time of the alternating current.

Abstract: A method of controlling the flow of molten metal in non-solidified portions of a strand (3) during continuous casting, and a device for application of the method. The device comprises a two-phase or plural-phase stirrer (1) arranged around a mould (6) that is open in opposite ends and that surrounds the strand (3), said stirrer (1) being arranged to generate a moving magnetic field in the melt, and at least one magnetic flow-conducting body (15) being placed between an inner periphery of said stirrer (1) and the outer periphery of the mould (6).

Abstract: A method for control of an extinction angle of a line-commutated converter in dependence on a minimum reference value for the extinction angle. The converter has a plurality of valves, each one of the plurality of valves having at least one semiconductor element capable of being fired, and the device has a unit for generating firing control pulses for a commutating valve in dependence on the minimum reference value of the extinction angle according to a given criterion for commutation of a direct current through the converter. The device has a unit for continuously forming an operating value of recovery time for the semiconductor element of a decommutating valve, and a unit for forming the minimum reference value of the extinction angle in dependence of the operating value.

Abstract: A system, method and computer program product for minimizing risks associated with meteorology dependent activity. Such activity may include operation of renewable power sources and the delivery of power output from those renewable sources for sale on a market. The system and method identify risks to market participants in the event of possible shortfall, and provide metrics and mitigation processes for addressing the risks before the contractual breaches occurs for failure to deliver power, or imbalances occurred in grid operations.