Breaking the ice [transmission line icing]

Icing of power transmission lines during winter storms is a persistent problem that causes outages and costs millions of dollars in repair expenses. High-frequency excitation at approximately 8-200 kHz has been proposed as a method to melt ice. The method works by a combination of two mechanisms. At these frequencies, ice is a lossy dielectric, causing heating directly in the ice. In addition, skin effect causes current to flow only in a thin layer on the surface of the line, causing resistive losses and consequent heating. In this article, we describe the design of systems to implement this method on lines up to 1000 km long. We also report experimental tests of deicing of a 1 m simulated line using dielectric losses in ice using a prototype system that applies 33 kV, 100 kHz power.