Wind turbine radar interference reduction using shroud and screens

Abstract

The benefits of wind turbines as a means for renewable energy generation are offset by the turbines’ creation of signal interference, such as Doppler shift, for radar systems used for air traffic control and weather forecasting. This restricts the placement of wind farms in the vicinity of radar installations. In this research, we investigate the effectiveness of placing a screen in front of a wind turbine in reducing turbine-generated Doppler shift interference. Software-defined radar (SDR) transmitting in continuous-wave mode was used to collect data required to analyze the signature of the Doppler returns. We built a rotator (i.e., an arm with metallic ball attached to one end) to establish the computation method to analyze the Doppler signature. Once the computation method was determined, measurements at various angles were carried out on the rotator with the aluminum shroud and screen included. Similar measurements were carried out on the scaled-down wind turbine model in Port Hueneme, CA, for comparison. This research shows that the SDR can be used to accurately measure the Doppler shift, and high-quality screens are effective in reducing the turbine-generated Doppler shift by more than 20 dB.