High-voltage ignitron rectifiers

THE DEVELOPMENT of new types of sealed ignitron tubes has made possible rectifier equipment which is capable of delivering high power at moderately high direct voltages. The lack of moving parts, long tube life, and practically unlimited emission of the pool cathode are advantages which provide a high degree of reliability. These factors bring to the high-voltage field the same high efficiency and high grade of performance which is characteristic of the low-voltage industrial rectifier equipments. A 2,500-kw unit and a 7,500-kw unit represent typical designs of 17,000-volt rectifiers. The former employs a 50-ampere sealed ignitron tube and the latter employs a 150-ampere tube. The 6-phase double-way power circuit is employed in both units because it provides better utilization of transformer capacity than other rectifier circuits. The double-way connection requires only three secondary windings on the rectifier transformer and only three high-voltage connections between the transformer and the tubes, thus requiring less insulating material on the a-c side than other power circuits.