Assessment of overhead transmission line icing using multivariable fuzzy logic control

Condition assessment of overhead transmission line icing is usually estimated by the threshold of equivalent thickness, leading to wrong decision because of technology and theoretical reasons. The overhead transmission line icing is affected by local meteorology parameters, such as relative humidity, ambient temperature and so on. Consequently, a method for assessing the conditions of overhead transmission line icing was proposed to improve the accuracy by using the multivariable fuzzy logic control, considering equivalent thickness of overhead transmission line mainly, local meteorology parameters, and ice cover duration. A hierarchical multixules structure of multivariable fuzzy logic controller and a set of fuzzy reasoning rules were set up. Furthermore, the accuracy and feasibility of this method presented was validated by the field data from China Southern Power Grid on-line monitoring and precaution system.