The icing of wind blades poses a serious threat to the operation of wind turbines. The application of superhydrophobic coatings on wind blades can serve as a potential anti-icing method. This study presents the findings of simulations of the icing environment of wind blades coated with hydrophobic silicone–acrylate resin in an artificial climate chamber. Artificial icing tests were performed on NACA7715 wind blades with four different silicone–acrylate resin coatings and on uncoated wind blades, with test performed at five different wind speeds and three different angles of attack. Results show that wind blade surfaces with higher hydrophobicity yield better anti-icing performance, and that the ice mass of the wind blades decreases with increasing wind speeds and angles of attack. In addition, variations in ice mass, shape, and distribution on different wind blades indicate that increased hydrophobicity can help limit the areas that are subject to freezing. Hydrophobicity can affect the air cavities of the ice deposited on the wind blades, and surfaces with increased hydrophobicity can lead to lower ice mass and less ice adhesion. In brief, surfaces with higher hydrophobicity demonstrate better anti-icing performance and benefit from active de-icing.

The water droplets on the surface of the overhead line (OHL) conductors are subject to an intensive electric field, which induces electric force on the charged liquid surface. Under the combined action of the surface tension as well as the electric force, movement and deformation can be observed on those water droplets. These result in a re-distribution of charge density on the liquid surface and therefore a re-distribution of electric force. In this paper, in order to strengthen the understanding of this complex multi-physics problem of interaction and mutual coupling, the vibration characteristics of water droplets under alternating electric fields is studied using the finite element method (FEM). Parameters such as the volume size of the water droplet, static/dynamic contact angle between the water droplet and conductor surface and voltage level are studied in relation to the vibration characteristics. The reproducible correlation between the phase and amplitude of the water droplet vibration on the surface of the conductor and the applied voltage is established. According to the calculated instantaneous electric field strength, it is explained that protrusions such as water droplets are the starting point of corona discharge.

Audible noise (AN) has been the main concern in recent years when considering electromagnetic environmental impact in designing overhead lines (OHLs). Driven by the increased demand of high voltage direct current (HVDC) transmission lines, a novel corona cage experiment is built in association with an acoustic simulation using the finite element method (FEM). The characteristics of the acoustic wave propagation within the testing hall are analyzed using FEM, and the optimized locations for AN detection are determined. On the basis of complying with measurement standards, the location of the measurement is selected to be closer to the sound source and further away from the reflecting surface, to generate more accurate measurement results. In the designated test hall for this paper, the influence of refraction and reflection of sound waves is not obvious. The attenuation of sound waves below 4 kHz is negligible, while for higher frequencies such as 4 kHz and 8 kHz it is significant. Finally, FEM simulation is used to optimize the location for measurement microphones, and further experiments are carried out to verify its accuracy.