Passive cancellation loops: Case study, model simulation and field test on a real HV overhead line in Italy: Electromagnetic computation and optimization

Installation of Passive Cancellation Loops (PCLs) is an efficient technique to mitigate the magnetic field generated by high voltage overhead lines (OHLs). PCLs were firstly introduced in the late '90s; even if, at present time, they are seldom installed, they are expected to become a widespread solution due to the increasing public attention to EMF exposure. More in detail, they can be a readily viable action to reduce public exposure of old existing OHLs, thus allowing higher power flow without exceeding the exposure limits. The purpose of this paper is to describe the tests carried out on a real 150 kV overhead lines in Italy, to assess the application of PCLs as a technique to reduce magnetic fields. Calculation models have also been developed and validated during the field tests. It has been confirmed from field test results that passive cancellation loops could be a valuable technique to mitigate magnetic field generated by transmission lines.