Electrical discharge and its impact on drivetrains of wind turbines

Defects in drivetrains of wind turbines are typically very costly due to the difficulty in accessing the defective components for repair and maintenance. Electrical discharge has been identified as one of the key root causes to defects in wind drivetrains. Improving the reliability of key wind turbine components has been attracting great research interest since the launch of the first wind turbine. In this paper, a study to understand the electrical discharge and its impact on wind drivetrains is presented. The root cause of electrical discharge in wind turbines is discussed. Field test is carried out on 1.5 MW DFIG (doubly-fed induction generator) wind turbines in practical environments. Suggestions are provided on the design of the wind turbine grounding and protection system to improve turbine reliability and reduce defect rates due to electrical discharge.