Abstract
Galloping-based energy harvester was developed for scavenging small-scale wind energy. An electromechanical coupled distributed parameter model is proposed based on the Euler-Bernoulli beam theory, quasi-steady approximation and Gauss law for electromagnetic energy harvesting from the galloping. The analytical solutions are derived using the equivalent structure method and confirmed by the numerical solutions of the full coupled model. In addition to the aerodynamic properties, modal shape and structural damping, the onset speed to galloping, tip displacement and harvested power are also functions of the electric damping and modified natural frequency. Such two critical variables depend on the natural frequency, coil inductance, coupling factor, load resistance and coil resistance. The bifurcation and performance analyses are conducted. Two optimal load resistances are found for the maximal power at fixed resistance ratio. When the resistance ratio changes, the optimal load resistance is unique. Larger resistance ratio, larger electromagnetic coupling factor and higher wind speed lead to higher maximal power. For small resistance ratio, there is an optimal magnet position to maximize the power. For large resistance ratio, the power increases monotonously with the magnet position. With small electromagnetic coupling factor, the power is higher with lower tip displacement at smaller coil inductance. The maximal power occurs at the medium coil inductance with large electromagnetic coupling factor.
