Impact of EMF on Current Ratings and Cable Systems

Numerous methods have been devised by electric utilities and various research organizations to manage power frequency magnetic fields levels in the vicinity of underground cable systems. The TB describes various methods of mitigation, their impact on cable rating and on construction; cost effectiveness, installation and operational costs are also analysed. Detailed formulas to compute impact on current rating are given for the most applied mitigation methods; example of circuit with shielding devices are presented and discussed. This TB deals only with systems of HV cables with balanced currents and no reference is done to environmental or biological effects of EMF, nor discussion about any specific levels of EMF.