Bus duct assembly for high-power rotary current transformer system

Abstract

A rotary transformer system ( ) comprises a rotatable shaft ( ) having at least one and preferably plural electrically conductive slip rings ( ) mounted thereon. The slip rings ( ) of the phase planes are electrically connected to their respective windings on rotor assembly ( ) by the bus conductors ( ). The bus conductors ( ) extend through respective phase isolated bus ducts ( ) formed interiorly in rotatable shaft ( ). The bus ducts ( ) have a buffer ( ) provided therebetween so that the bus ducts ( ) are not in physical contact, but are spaced apart and separated. A mouth ( ) and annulus ( ) of each bus duct ( ) extend through a cover plate ( ). The cover plate ( ) is secured by fasteners ( ) through insulated spacers ( ) and is held slight aloft above the circumference of rotatable shaft ( ), thereby insulating cover plate ( ) from rotatable shaft ( ). The cover plates ( ) of adjacent bus ducts ( ) are electrically connected by a flux plate ( ). The flux plate ( ) extends around the exterior of rotatable shaft ( ) and is secured to rotatable shaft ( ) by fastener assemblies ( ). Each phase conductor ( ) is thus in its own grounded metal enclosure, e.g., bus duct ( ). The isolated phase bus ensures that any fault or electrical failure or arc-over will occur first to ground before becoming a phase to phase fault.