Power Transmission by Direct Current (PDF)

The direct current transmission scheme linking the island of Gotland to the main­ land of Sweden by means of a submarine cable under the Baltic Sea is the first commercial realisation of a modern technique for the transmission of electrical energy. It is certainly not accidental that this pioneering initiative was allotted to the Gotland scheme. Various viewpoints may be presented regarding this, but the essential factor relates to the circumstances that permitted the magnitude ofthe transmitted power to be given a value which would not have been technically or economically feasible for any other project. The power, on the one hand, was sufficiently small to justify the risk associated with such a new venture, for it fell within limits acceptable both to ASEA as the manufacturer and to the Swedish State Power Board as the customer. On the other hand, the power was large enough to demonstrate the technical and economic characteristics of the new system and to provide the opportunity of gaining invaluable experience that could be applied to future large-scale transmission systems. In 1954 a team under the direction of Dr. Uno Lamm successfully commissioned the Gotland scheme, representing the culmination of many years of intensive development work.