A wind-flutter energy converter for powering wireless sensors

Abstract

This paper describes a low-speed wind energy harvesting system that transfers aerodynamically induced flutter energy into electrical energy. A random airflow generates mechanical vibrations due to the fluid–structure interaction between a flexible belt and the airflow. An electromagnetic resonator with copper coils and a permanent magnet is designed to efficiently harvest electrical energy from the induced mechanical vibrations. Different groups of springs are compared at various wind conditions to maximize the power output. Typically ∼7 mW of electrical energy can be obtained at ∼3 m/s wind speed with a 1 m long belt. A power conditioning circuit with a charge pump and a DC–DC converter is used to convert the generated voltage into a stable 3.3 V DC for consumption. It is demonstrated that this generator can be used to drive a commercial wireless temperature sensor.