An Inertial Noncontact Piezoelectric Rotary Energy Harvester with Linear Reciprocating Motion

Abstract

Herein, an inertial noncontact piezoelectric rotary energy harvester with linear reciprocating motion (L‐PREH) is presented. The existing piezoelectric rotary harvester employing gravity excitation has limited performance when the rotation speed is high due to the negative influence of centrifugal force. L‐PREH translates rotational motion into linear motion via the transmission chain and employs inertial force excitation to overcome high‐speed performance limitations. Using the Euler–Bernoulli beam theory, the motion governing equations of piezoelectric transducers have been derived, and an electromechanical coupling model has been constructed. Moreover, the piezoelectric transducer is simulated and analyzed. The control variable approach is used to explore the key parameters impacting output performance. When the mass is positioned in symmetrical method, the guide rod is fixed in noncentral place, the limiter is fixed in longest distance, the distance between the mass's center and the main frame is the maximum, and the rotating speed is 450 RPM, the maximum peak‐to‐peak output voltage of an L‐PREH single transducer is 24 V. The highest power of two piezoelectric transducers linked in parallel with a load resistance of 400 kΩ is 0.27 mW, which can light up more than 70 light‐emitting diodes. The L‐PREH can drive low‐power devices.