Simulation and Analysis on Dynamic Distribution of Space Charge of Wind Turbine Blade Tip Corona Discharge at Different Rotation Angles

Abstract

Aiming at the problem of unclear distribution characteristics of space charge near the blade tip of the wind turbine, this paper used the simulation modelling method to simulate corona discharge of the blade tip at different angles. The relative motion between the wind turbine’s blade and surrounding air when the wind turbine rotates is equivalent to the high-speed airflow through the blade tip. A two-dimensional positive space charge distribution model of corona discharge was established considering the attachment and collision between positive ions and other ions. Based on the above model, the blade tip corona discharge was simulated, and the distribution and migration characteristics of positive space charge were obtained when the blades were at different angles. It is found that, under the lightning electric field and high-speed airflow, the transfer velocity of space charge provided by the high-speed airflow flowing through the blade tip is much higher than that provided by electric field traction. Therefore, the transfer and diffusion direction of space charge in the blade tip is mainly determined by the direction of the high-speed airflow at the blade tip. At the same time, the space charge no longer symmetrically distributed in space causes space potential distortion, the potential on the left side (windward side) of the blade tip air-termination is higher than that on the right side at the same height, and the direction of the maximum electric field near the blade tip air-termination shifts to the left, and the electric field amplitude also increases compared with that in the static condition. The work in this paper can provide a basis for the initiation and development calculation of upstream pilot wind turbine blades.