How to reduce skin effect?

In Article 4 (AC Resistance), we talked about Skin and proximity effect. In this article we will see how we reduce skin effect in a current carrying conductor. We know that a changing current in a conductor produces magnetic field and a changing magnetic field produces back emf (Electro motive force) which is in a opposite direction to current flowing through the conductor. This effect is known as skin effect.

To tackle the problem of skin effect, a conductor with large cross sectional area is developed by splitting it in a several segments of stranded sectors known as Milliken conductor. Milliken Conductor is one of the names or types of construction on High Voltage Cable ( HV ) and also on the Extra High Voltage Cable ( EHV ) . Voltage Range varies from 63-161 kV , 220-230 , 330-500 kV . Milliken Conductor is used for large conductor cross-section , generally ranging from 1000, 1200, 1600, 2000 , 2500 , 3000 mm2 . For size underneath as 400 , 500 , 630 and 800 mm2 , simply use ordinary construction Circular Compacted Strand . This design minimises the skin effect by dividing the current equally through each segment separately. during assembling one separator tape is introduced between two sectors to keep each one isolated from other. The outer surface of conductor remains smooth after compacting and laying should be absolutely free from any kind of defect. In some cases enamelled wires are also stranded together to form a sector of Milliken conductor. Hence skin effect is reduced to a large extent as current flow through wires individually.

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