Analysis of Atmospheric Icing Events Observed at the Mount Valin Test Site During the 1995-96 Season

摘要

In northern countries, ice loads are very important for the design and reliability of exposed structures, particularly power lines and communication networks. A test site located on the Mount Valin, near Chicoutimi (Quebec) Canada, is used since 1985 to monitor atmospheric ice accretions on non-energized test lines. This test site is exposed to severe atmospheric conditions, ranging from freezing rain to in-cloud icing, during about seven months each year. The test site is equipped with two perpendicular test lines instrumented with load cells, a temperature gauge, an anemometer, an ice detector, a precipitation gauge, data loggers and a video-camera. The main test line is 96.5 m in span and supports a 12.5-mm conductor, a 35-mm ACSR conductor and a four 35-mm conductor bundle. The second test line, 32.6 m in span, is normal to the first one and used for comparison purposes. Typical ice mass accretions observed on the conductors during the 1995-1996 winter season are presented and analyzed. The meteorological information recorded on the site during the icing periods is also presented and used to characterize the type of icing events. Using statistical analysis, values of main icing parameters on the different conductors are calculated and compared for freezing rain and in-cloud icing.