Scavenging energy from a vibrating building using distributed electromagnetic energy harvesters with nonlinear circuits

The energy scavenged from a vibrating building installed with distributed electromagnetic energy harvesters under random excitation is analyzed. Each harvester is connected to an energy harvesting circuit made of a full-wave bridge rectifier connecting a resistor in parallel with a capacitor. Statistical linearization is adopted to estimate the stationary response of the harvester-structure system. As an illustrative example, a 20-story building equipped with 16 harvesters on each story is examined. Results show that the scavenged energy mainly concentrates at the higher stories. The vibration mitigation and energy scavenging performance of the harvesters can be enhanced simultaneously with the proper design of harvesters and circuits. Gradient ascent approach with the first-order perturbation approximation is proposed to determine the optimal design of distributed harvesters with nonlinear circuits that maximizes the total mean output power. Results show that output power decreases due to circuit nonlinearity. The maximum total mean output power obtained from the 20-story building under wind excitations with mean speed of 5 m/s is around 1.32–2.17 kW for harvesters having short-circuit damping coefficient ranging 100–300 kNs/m. These results show that scavenging energy from structural vibration is a feasible technology even considering the negative effect of circuit nonlinearity.