A novel electromagnetic field shaper for pipe-type cable systems

A novel electromagnetic field shaper designed to reduce the electrical losses and increase the current carrying capacity of pipe-type cable systems was conceived in 1983. The salient feature of this field is that, in addition to significantly reducing the eddy current losses in the pipe or cable enclosure, it also reduces the losses in the cables due to their proximity to the metallic enclosure. The field shaper effectively minimizes the ratio of the AC over the DC resistance of the cables, and consequently maximizes the ampacity of the system, at a relatively low increase in the initial cost of the system. The authors introduce the concept of the electromagnetic field shaper and present a general analysis of the loss reduction mechanisms associated with its design features and parameters